Add support for triggering webhook notifications on wiki changes.

This PR contains frontend and backend for webhook notifications on wiki actions (create a new page, rename a page, edit a page and delete a page). The frontend got a new checkbox under the Custom Event -> Repository Events section. There is only one checkbox for create/edit/rename/delete actions, because it makes no sense to separate it and others like releases or packages follow the same schema.

![image](https://user-images.githubusercontent.com/121972/177018803-26851196-831f-4fde-9a4c-9e639b0e0d6b.png)

The actions itself are separated, so that different notifications will be executed (with the "action" field). All the webhook receivers implement the new interface method (Wiki) and the corresponding tests.

When implementing this, I encounter a little bug on editing a wiki page. Creating and editing a wiki page is technically the same action and will be handled by the ```updateWikiPage``` function. But the function need to know if it is a new wiki page or just a change. This distinction is done by the ```action``` parameter, but this will not be sent by the frontend (on form submit). This PR will fix this by adding the ```action``` parameter with the values ```_new``` or ```_edit```, which will be used by the ```updateWikiPage``` function.

I've done integration tests with matrix and gitea (http).

![image](https://user-images.githubusercontent.com/121972/177018795-eb5cdc01-9ba3-483e-a6b7-ed0e313a71fb.png)

Fix #16457

Signed-off-by: Aaron Fischer <mail@aaron-fischer.net>

* gofumpt -w -l .

* gofumpt -w -l -extra .

* Add linter

* manual fix

* change make fmt

* Add an abstract json layout to make it's easier to change json library

* Fix import

* Fix import sequence

* Fix blank lines

* Fix blank lines

This PR removes multiple unneeded fields from the `HookTask` struct and adds the two headers `X-Hub-Signature` and `X-Hub-Signature-256`.

## :warning: BREAKING :warning: 

* The `Secret` field is no longer passed as part of the payload.
* "Breaking" change (or fix?): The webhook history shows the real called url and not the url registered in the webhook (`deliver.go`@129).

Close #16115
Fixes #7788
Fixes #11755

Co-authored-by: zeripath <art27@cantab.net>

* Added tests for MS Teams.

* Added tests for Dingtalk.

* Added tests for Telegram.

* Added tests for Feishu.

* Added tests for Discord.

* Added tests for closed issue and pullrequest comment.

* Added tests for Matrix.

* Trim all spaces.

* Added tests for Slack.

* Added JSONPayload tests.

* Added general tests.

* Replaced duplicated code.

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

* Migrate to use jsoniter

* fix tests

* update gitea.com/go-chi/binding

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>

* Fix bug for webhook

* Fix bug for feishu

* Move webhook type from int to string

* rename webhook_services

* finish refactor

* Fix merge

* Ignore unnecessary ci

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: zeripath <art27@cantab.net>

* Refactor webhook payload convertion

* Fix lint

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

* Fix webhook comment handling type cast panic

* Handle HookIssueReviewed action in webhook

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

* Initial work

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Add PR reviews and API coverage

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Split up events

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Add migration and locale

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Format

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Revert IsPull

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Fix comments

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Fix tests

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Fix PR reviews

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Fix issue_comment

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Make fmt

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Migrations

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Backwards compatible API

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Fix feishu

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Move session commit

Signed-off-by: jolheiser <john.olheiser@gmail.com>

Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: guillep2k <18600385+guillep2k@users.noreply.github.com>

Add feishu webhook support